The present invention relates to hydroxamate compounds which are inhibitors of histone deacetylase. The inventive compounds are useful as pharmaceuticals for the treatment of proliferative diseases.
Reversible acetylation of histones is a major regulator of gene expression that acts by altering accessibility of transcription factors to DNA. In normal cells, histone deacetylase (HDA) and histone acetyltrasferase together control the level of acetylation of histones to maintain a balance. Inhibition of HDA results in the accumulation of hyperacetylated histones, which results in a variety of cellular responses.
Inhibitors of HDA have been studied for their therapeutic effects on cancer cells. For example, butyric acid and its derivatives, including sodium phenylbutyrate, have been reported to induce apoptosis in vitro in human colon carcinoma, leukemia and retinoblastoma cell lines. However, butyric acid and its derivatives are not useful pharmacological agents because they tend to be metabolized rapidly and have a very short half-life in vivo. Other inhibitors of HDA that have been widely studied for their anti-cancer activities are trichostatin A and trapoxin. Trichostatin A is an antifungal and antibiotic and is a reversible inhibitor of mammalian HDA Trapoxin is a cyclic tetrapeptide, which is an irreversible inhibitor of mammalian HDA. Although trichostatin and trapoxin have been studied for their anti-cancer activities, the in vivo instability of the compounds makes them less suitable as anti-cancer drugs. There remains a need for an active compound that is suitable for treating tumors, including cancerous tumors, that is highly efficacious and stable.
The present invention provides efficacious deacetylase inhibitor compounds that are useful as pharmaceutical agents having the formula (I): 
wherein
R1 is H, halo, or a straight chain C1-C6 alkyl (especially methyl, ethyl or n-propyl, which methyl, ethyl and n-propyl substituents are unsubstituted or substituted by one or more substituents described below for alkyl substituents);
R2 is selected from H, C1-C10 alkyl, (e.g. methyl, ethyl or xe2x80x94CH2CH2xe2x80x94OH), C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, C4-C9 heterocycloalkylalkyl, cycloalkylalkyl (e.g., cyclopropylmethyl), aryl, heteroaryl, arylalkyl (e.g. benzyl), heteroarylalkyl (e.g. pyridylmethyl), xe2x80x94(CH2)nC(O)R6, xe2x80x94(CH2)nOC(O)R6, amino acyl, HONxe2x80x94C(O)xe2x80x94CHxe2x95x90C(R1)-aryl-alkyl- and xe2x80x94(CH2)nR7;
R3 and R4 are the same or different and independently H, C1-C6 alkyl, acyl or acylamino, or R3 and R4 together with the carbon to which they are bound represent Cxe2x95x90O, Cxe2x95x90S, or Cxe2x95x90NR8, or R2 together with the nitrogen to which it is bound and R3 together with the carbon to which it is bound can form a C4-C9 heterocycloalkyl, a heteroaryl, a polyheteroaryl, a non-aromatic polyheterocycle, or a mixed aryl and non-aryl polyheterocycle ring;
R5 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, acyl, aryl, heteroaryl, arylalkyl (e.g. benzyl), heteroarylalkyl (e.g. pyridylmethyl), aromatic polycycles, non-aromatic polycycles, mixed aryl and non-aryl polycycles, polyheteroaryl, non-aromatic polyheterocycles, and mixed aryl and non-aryl polyheterocycles;
n, n1, n2 and n3 are the same or different and independently selected from 0-6, when n1 is 1-6, each carbon atom can be optionally and independently substituted with R3 and/or R4;
X and Y are the same or different and independently selected from H, halo, C1-C4 alkyl, such as CH3 and CF3, NO2, C(O)R1, OR9, SR9, CN, and NR10R11;
R6 is selected from H, C1-C6 alkyl, C4 -C9 cycloalkyl, C4-C9 heterocycloalkyl, cycloalkylalkyl (e.g., cyclopropylmethyl), aryl, heteroaryl, arylalkyl (e.g., benzyl, 2-phenylethenyl), heteroarylalkyl (e.g., pyridylmethyl), OR12, and NR13R14;
R7 is selected from OR15, SR15, S(O)R16, SO2R17, NR13R14, and NR12SO2R6;
R8 is selected from H, OR15, NR13R14, C1-C6 alkyl, C4 -C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl (e.g., benzyl), and heteroarylalkyl (e.g., pyridylmethyl);
R9 is selected from C1-C4 alkyl, for example, CH3 and CF3, C(O)-alkyl, for example C(O)CH3, and C(O)CF3;
R10 and R11 are the same or different and independently selected from H, C1-C4 alkyl, and xe2x80x94C(O)-alkyl;
R12 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, C4-C9 heterocycloalkylalkyl, aryl, mixed aryl and non-aryl polycycle, heteroaryl, arylalkyl (e.g., benzyl), and heteroarylalkyl (e.g., pyridylmethyl);
R13 and R14 are the same or different and independently selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl (e.g., benzyl), heteroarylalkyl (e.g., pyridylmethyl), amino acyl, or R13 and R14 together with the nitrogen to which they are bound are C4-C9 heterocycloalkyl, heteroaryl, polyheteroaryl, non-aromatic polyheterocycle or mixed aryl and non-aryl polyheterocycle;
R15 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl and (CH2)mZR12;
R16 is selected from C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, polyheteroaryl, arylalkyl, heteroarylalkyl and (CH2)mZR12;
R17 is selected from C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, aromatic polycycles, heteroaryl, arylalkyl, heteroarylalkyl, polyheteroaryl and NR13R14;
m is an integer selected from 0 to 6; and
Z is selected from O NR13, S and S(O),
or a pharmaceutically acceptable salt thereof.
The compounds of the present invention are suitable as active agents in pharmaceutical compositions that are efficacious particularly for treating cellular proliferative ailments. The pharmaceutical composition has ia pharmaceutically effective amount of the present active agent along with other pharmaceutically acceptable exicipients, carriers, fillers, diluents and the like. The term pharmacuetically effective amount as used herein indicates an amount necessary to administer to a host to achieve a therapeutic result, especially an anti-tumor effect, e.g., inhibition of proliferation of malignant cancer cells, benign tumor cells or other proliferative cells.
The present invention provides hydroxamate compounds, e.g., hydroxamic acids, that are inhibitors of deacetylases, preferably inhibitors of histone deacetylases. The hydroxamate compounds are highly suitable for treating tumors, including cancerous tumors. The hydroxamate compounds of the present invention have the following structure (I): 
wherein
R1 is H, halo, or a straight chain C1-C6 alkyl (especially methyl, ethyl or n-propyl, which methyl, ethyl and n-propyl substituents are unsubstituted or substituted by one or more substituents described below for alkyl substituents);
R2 is selected from H, C1-C10 alkyl, (preferably C1-C6 alkyl, e.g. methyl, ethyl or xe2x80x94CH2CH2xe2x80x94OH), C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, C4-C9 heterocycloalkylalkyl, cycloalkylalkyl (e.g., cyclopropylmethyl), aryl, heteroaryl, arylalkyl (e.g. benzyl), heteroarylalkyl (e.g. pyridylmethyl), xe2x80x94(CH2)nC(O)R6, xe2x80x94(CH2)nOC(O)R6, amino acyl, HONxe2x80x94C(O)xe2x80x94CHxe2x95x90C(R1)-aryl-alkyl- and xe2x80x94(CH2)nR7;
R3 and R4 are the same or different and independently H, C1-C6 alkyl, acyl or acylamino, or R3 and R4 together with the carbon to which they are bound represent Cxe2x95x90O, Cxe2x95x90S, or Cxe2x95x90NR8, or R2 together with the nitrogen to which it is bound and R3 together with the carbon to which it is bound can form a C4-C9 heterocycloalkyl, a heteroaryl, a polyheteroaryl, a non-aromatic polyheterocycle, or a mixed aryl and non-aryl polyheterocycle ring;
R5 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, acyl, aryl, heteroaryl, arylalkyl (e.g. benzyl), heteroarylalkyl (e.g. pyridylmethyl), aromatic polycycles, non-aromatic polycycles, mixed aryl and non-aryl polycycles, polyheteroaryl, non-aromatic polyheterocycles, and mixed aryl and non-aryl polyheterocycles;
n, n1, n2 and n3 are the same or different and independently selected from 0-6, when n1 is 1-6, each carbon atom can be optionally and independently substituted with R3 and/or R4;
X and Y are the same or different and independently selected from H, halo, C1-C4alkyl, such as CH3 and CF3, NO2, C(O)R1, OR9, SR9, CN, and NR10R11;
R6 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, cycloalkylalkyl (e.g., cyclopropylmethyl), aryl, heteroaryl, arylalkyl (e.g., benzyl, 2-phenylethenyl), heteroarylalkyl (e.g., pyridylmethyl), OR12, and NR13R14;
R7 is selected from OR15, SR15, S(O)R16, SO2R17, NR13R14, and NR12SO2R6;
R8 is selected from H, OR15, NR13R14, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl (e.g., benzyl), and heteroarylalkyl (e.g., pyridylmethyl);
R9 is selected from C1-C4alkyl, for example, CH3 and CF3, C(O)-alkyl, for example C(O)CH3, and C(O)CF3;
R10 and R11 are the same or different and independently selected from H, C1-C4 alkyl, and xe2x80x94C(O)-alkyl;
R12 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, C4-C9 heterocycloalkylalkyl, aryl, mixed aryl and non-aryl polycycle, heteroaryl, arylalkyl (e.g., benzyl), and heteroarylalkyl (e.g., pyridylmethyl);
R13 and R14 are the same or different and independently selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl (e.g., benzyl), heteroarylalkyl (e.g., pyridylmethyl), amino acyl, or R13 and R14 together with the nitrogen to which they are bound are C4-C9 heterocycloalkyl, heteroaryl, polyheteroaryl, non-aromatic polyheterocycle or mixed aryl and non-aryl polyheterocycle;
R15 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl and (CH2)mZR12;
R16 is selected from C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, polyheteroaryl, arylalkyl, heteroarylalkyl and (CH2)mZR12;
R17 is selected from C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, aromatic polycycles, heteroaryl, arylalkyl, heteroarylalkyl, polyheteroaryl and NR13R14;
m is an integer selected from 0 to 6; and
Z is selected from O NR13, S and S(O),
or a pharmaceutically acceptable salt thereof.
As appropriate, unsubstituted means that there is no substituent or that the only substituents are hydrogen.
Halo substituents are selected from fluoro, chloro, bromo and iodo, preferably fluoro or chloro.
Alkyl substituents include straight and branched C1-C6alkyl, unless otherwise noted. Examples of suitable straight and branched C1-C6alkyl substituents include methyl, ethyl, n-propyl, 2-propyl, n-butyl, sec-butyl, t-butyl, and the like. Unless otherwise noted, the alkyl substituents include both unsubstituted alkyl groups and alkyl groups that are substituted by one or more suitable substituents, including unsaturation (i.e. there are one or more double or triple Cxe2x80x94C bonds), acyl, cycloalkyl, halo, oxyalkyl, alkylamino, aminoalkyl, acylamino and OR15, for example, alkoxy. Preferred substituents for alkyl groups include halo, hydroxy, alkoxy, oxyalkyl, alkylamino, and aminoalkyl.
Cycloalkyl substituents include C3-C9 cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like, unless otherwise specified. Unless otherwise noted, cycloalkyl substituents include both unsubstituted cycloalkyl groups and cycloalkyl groups that are substituted by one or more suitable substituents, including C1-C6 alkyl, halo, hydroxy, aminoalkyl, oxyalkyl, alkylamino, and OR15, such as alkoxy. Preferred substituents for cycloalkyl groups include halo, hydroxy, alkoxy, oxyalkyl, alkylamino and aminoalkyl.
The above discussion of alkyl and cycloalkyl substituents also applies to the alkyl portions of other substituents, such as without limitation, alkoxy, alkyl amines, alkyl ketones, arylalkyl, heteroarylalkyl, alkylsulfonyl and alkyl ester substituents and the like.
Heterocycloalkyl substituents include 3 to 9 membered aliphatic rings, such as 4 to 7 membered aliphatic rings, containing from one to three heteroatoms selected from nitrogen, sulfur, oxygen. Examples of suitable heterocycloalkyl substituents include pyrrolidyl, tetrahydrofuryl, tetrahydrothiofuranyl, piperidyl, piperazyl, tetrahydropyranyl, morphilino, 1,3-diazapane, 1,4-diazapane, 1,4-oxazepane, and 1,4-oxathiapane. Unless otherwise noted, the rings are unsubstituted or substuted on the carbon atoms by one or more suitable substituents, including C1-C6 alkyl, C4-C9 cycloalkyl, aryl, heteroaryl, arylalkyl (e.g., benzyl), and heteroarylalkyl (e.g., pyridylmethyl), halo, amino, alkyl amino and OR15, for example alkoxy. Unless otherwise noted, nitrogen heteroatoms are unsubstituted or substituted by H, C1-C4 alkyl, arylalkyl (e.g., benzyl), and heteroarylalkyl (e.g., pyridylmethyl), acyl, aminoacyl, alkylsulfonyl, and arylsulfonyl.
Cycloalkylalkyl substituents include compounds of the formula xe2x80x94CH2)n5-cycloalkyl wherein n5 is a number from 1-6. Suitable alkylcycloalkyl substituents include cyclopentylmethyl-, cyclopentylethyl, cyclohexylmethyl and the like. Such substituents are unsubstituted or substituted in the alkyl portion or in the cycloalkyl portion by a suitable substituent, including those listed above for alkyl and cycloalkyl.
Aryl substituents include unsubstituted phenyl and phenyl substituted by one or more suitable substituents, including C1-C6 alkyl, cycloalkylalkyl (e.g., cyclopropylmethyl), O(CO)alkyl, oxyalkyl, halo, nitro, amino, alkylamino, aminoalkyl, alkyl ketones, nitrile, carboxyalkyl, alkylsulfonyl, aminosulfonyl, arylsulfonyl, and OR15, such as alkoxy. Preferred substituents include including C1-C6 alkyl, cycloalkyl (e.g., cyclopropylmethyl), alkoxy, oxyalkyl, halo, nitro, amino, alkylamino, aminoalkyl, alkyl ketones, nitrile, carboxyalkyl, alkylsulfonyl, arylsulfonyl, and aminosulfonyl. Examples of suitable aryl groups include C1-C4alkylphenyl, C1-C4alkoxyphenyl, trifluoromethylphenyl, methoxyphenyl, hydroxyethylphenyl, dimethylaminophenyl, aminopropylphenyl, carbethoxyphenyl, methanesulfonylphenyl and tolylsulfonylphenyl.
Aromatic polycycles include naphthyl, and naphthyl substituted by one or more suitable substituents, including C1-C6 alkyl, alkylcycloalkyl (e.g., cyclopropylmethyl), oxyalkyl, halo, nitro, amino, alkylamino, aminoalkyl, alkyl ketones, nitrile, carboxyalkyl, alkylsulfonyl, arylsulfonyl, aminosulfonyl and OR15, such as alkoxy.
Heteroaryl substituents include compounds with a 5 to 7 member aromatic ring containing one or more heteroatoms, for example from 1 to 4 heteroatoms, selected from N, O and S. Typical heteroaryl substituents include furyl, thienyl, pyrrole, pyrazole, triazole, thiazole, oxazole, pyridine, pyrimidine, isoxazolyl, pyrazine and the like. Unless otherwise noted, heteroaryl substituents are unsubstituted or substituted on a carbon atom by one or more suitable substituents, including alkyl, the alkyl substituents identified above, and another heteroaryl substituent. Nitrogen atoms are unsubstituted or substituted, for example by R13; especially useful N substituents include H, C1-C4 alkyl, acyl, aminoacyl, and sulfonyl.
Arylalkyl substituents include groups of the formula xe2x80x94(CH2)n5-aryl, xe2x80x94(CH2)n5-1xe2x80x94(CHaryl)xe2x80x94(CH2)n5-aryl or xe2x80x94(CH2)n5-1CH(aryl)(aryl) wherein aryl and n5 are defined above. Such arylalkyl substituents include benzyl, 2-phenylethyl, 1-phenylethyl, tolyl-3-propyl, 2-phenylpropyl, diphenylmethyl, 2-diphenylethyl, 5,5-dimethyl-3-phenylpentyl and the like. Arylalkyl substituents are unsubstituted or substituted in the alkyl moiety or the aryl moiety or both as described above for alkyl and aryl substituents.
Heteroarylalkyl substituents include groups of the formula xe2x80x94(CH2)n5-heteroaryl wherein heteroaryl and n5 are defined above and the bridging group is linked to a carbon or a nitrogen of the heteroaryl portion, such as 2- , 3- or 4-pyridylmethyl, imidazolylmethyl, quinolylethyl, and pyrrolylbutyl. Heteroaryl substituents are unsubstituted or substituted as discussed above for heteroaryl and alkyl substituents.
Amino acyl substituents include groups of the formula xe2x80x94C(O)xe2x80x94(CH2)nxe2x80x94C(H)(NR13R14)xe2x80x94(CH2)nxe2x80x94R5 wherein n, R13, R14 and R5 are described above. Suitable aminoacyl substituents include natural and non-natural amino acids such as glycinyl, D-tryptophanyl, L-lysinyl, D- or L-homoserinyl, 4-aminobutryic acyl, xc2x1-3-amin-4-hexenoyl.
Non-aromatic polycycle substituents include bicyclic and tricyclic fused ring systems where each ring can be 4-9 membered and each ring can contain zero, 1 or more double and/or triple bonds. Suitable examples of non-aromatic polycycles include decalin, octahydroindene, perhydrobenzocycloheptene, perhydrobenzo-[f]-azulene. Such substituents are unsubstituted or substituted as described above for cycloalkyl groups.
Mixed aryl and non-aryl polycycle substituents include bicyclic and tricyclic fused ring systems where each ring can be 4-9 membered and at least one ring is aromatic. Suitable examples of mixed aryl and non-aryl polycycles include methylenedioxyphenyl, bis-methylenedioxyphenyl, 1,2,3,4-tetrahydronaphthalene, dibenzosuberane, dihdydroanthracene, 9H-fluorene. fluorene. Such substituents are unsubstituted or substituted by nitro or as described above for cycloalkyl groups.
Polyheteroaryl substituents include bicyclic and tricyclic fused ring systems where each ring can independently be 5 or 6 membered and contain one or more heteroatom, for example, 1, 2, 3, or 4 heteroatoms, chosen from O, N or S such that the fused ring system is aromatic. Suitable examples of polyheteroaryl ring systems include quinoline, isoquinoline, pyridopyrazine, pyrrolopyridine, furopyridine, indole, benzofuran, benzothiofuran, benzindole, benzoxazole, pyrroloquinoline, and the like. Unless otherwise noted, polyheteroaryl substituents are unsubstituted or substituted on a carbon atom by one or more suitable substituents, including alkyl, the alkyl substituents identified above and a substituent of the formula xe2x80x94Oxe2x80x94(CH2CHxe2x95x90CH(CH3)(CH2))1-3H. Nitrogen atoms are unsubstituted or substituted, for example by R13; especially useful N substituents include H, C1-C4 alkyl, acyl, aminoacyl, and sulfonyl.
Non-aromatic polyheterocyclic substituents include bicyclic and tricyclic fused ring systems where each ring can be 4-9 membered, contain one or more heteroatom, for example, 1, 2, 3, or 4 heteroatoms, chosen from O, N or S and contain zero or one or more Cxe2x80x94C double or triple bonds. Suitable examples of non-aromatic polyheterocycles include hexitol, cis-perhydro-cyclohepta[b]pyridinyl, decahydro-benzo[f][1,4]oxazepinyl, 2,8-dioxabicyclo[3.30]octane, hexahydro-thieno[3,2-b]thiophene, perhydropyrrolo[3,2-b]pyrrole, perhydronaphthyridine, perhydro-1H-dicyclopenta[b,e]pyran. Unless otherwise noted, non-aromatic polyheterocyclic substituents are unsubstituted or substituted on a carbon atom by one or more substituents, including alkyl and the alkyl substituents identified above. Nitrogen atoms are unsubstituted or substituted, for example, by R13; especially useful N substituents include H, C1-C4 alkyl, acyl, aminoacyl, and sulfonyl.
Mixed aryl and non-aryl polyheterocycles substituents include bicyclic and tricyclic fused ring systems where each ring can be 4-9 membered, contain one or more heteroatom chosen from O, N or S, and at least one of the rings must be aromatic. Suitable examples of mixed aryl and non-aryl polyheterocycles include 2,3-dihydroindole, 1,2,3,4-tetrahydroquinoline, 5,11-dihydro-10H-dibenz[b,e][1,4]diazepine, 5H-dibenzo[b,e][1,4]diazepine, 1,2-dihydropyrrolo[3,4-b][1,5]benzodiazepine, 1,5-dihydro-pyrido[2,3-b][1,4]diazepin-4-one, 1,2,3,4,6,11-hexahydro-benzo[b]pyrido[2,3-e][1,4]diazepin-5-one. Unless otherwise noted, mixed aryl and non-aryl polyheterocyclic substituents are unsubstituted or substituted on a carbon atom by one or more suitable substituents, including, xe2x80x94Nxe2x80x94OH, xe2x95x90Nxe2x80x94OH, alkyl and the alkyl substituents identified above. Nitrogen atoms are unsubstituted or substituted, for example, by R13; especially useful N substituents include H, C1-C4 alkyl, acyl, aminoacyl, and sulfonyl.
Amino substituents include primary, secondary and tertiary amines and in salt form, quatemary amines. Examples of amino substituents include mono- and di-alkylamino, mono- and di-aryl amino, mono- and di-arylalkyl amino, aryl-arylalkylamino, alkyl-arylamino, alkyl-arylalkylamino and the like.
Sulfonyl substituents include alkylsulfonyl and arylsulfonyl, for example methane sulfonyl, benzene sulfonyl, tosyl and the like.
Acyl substituents include groups of formula xe2x80x94C(O)xe2x80x94W, xe2x80x94OC(O)xe2x80x94W, xe2x80x94C(O)xe2x80x94Oxe2x80x94W or xe2x80x94C(O)NR13R14, where W is R16, H or cycloalkylalkyl.
Acylamino substituents include substituents of the formula xe2x80x94N(R12)C(O)xe2x80x94W, xe2x80x94N(R12)C(O)xe2x80x94Oxe2x80x94W, and xe2x80x94N(R12)C(O)xe2x80x94NHOH and R12 and W are defined above.
The R2 substituent HONxe2x80x94C(O)CHxe2x95x90C(R1)-aryl-alkyl- is a group of the formula 
Preferences for each of the substituents include the following:
R1 is H, halo, or a straight chain C1-C4 alkyl;
R2 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, alkylcycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, xe2x80x94(CH2)nC(O)R6, amino acyl, and xe2x80x94(CH2)nR7;
R3 and R4 are the same or different and independently selected from H, and C1-C6 alkyl, or R3 and R4 together with the carbon to which they are bound represent Cxe2x95x90O, Cxe2x95x90S, or Cxe2x95x90NR8;
R5 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, a aromatic polycycle, a non-aromatic polycycle, a mixed aryl and non-aryl polycycle, polyheteroaryl, a non-aromatic polyheterocycle, and a mixed aryl and non-aryl polyheterocycle;
n, n1, n2 and n3 are the same or different and independently selected from 0-6, when n1 is 1-6, each carbon atom is unsubstituted or independently substituted with R3 and/or R4;
X and Y are the same or different and independently selected from H, halo, C1-C4 alkyl, CF3, NO2, C(O)R1, OR9, SR9, CN, and NR10R11;
R6 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, alkylcycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, OR12, and NR13R14;
R7 is selected from OR15, SR15, S(O)R16, SO2R17, NR13R14, and NR12SO2R6;
R8 is selected from H, OR15, NR13R14, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl, and heteroarylalkyl;
R9 is selected from C1-C4 alkyl and C(O)-alkyl;
R10 and R11 are the same or different and independently selected from H, C1-C4 alkyl, and xe2x80x94C(O)-alkyl;
R12 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl, and heteroarylalkyl;
R13 and R14 are the same or different and independently selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl and amino acyl;
R15 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl and (CH2)mZR12;
R16 is selected from C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl and (CH2)mZR12;
R17 is selected from C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocydoalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl and NR13R14;
m is an integer selected from 0 to 6; and
Z is selected from O, NR13, S, S(O),
or a pharmaceutically acceptable salt thereof.
Useful compounds of the formula (I) include those wherein each of R1, X, Y, R3, and R4 is H, including those wherein one of n2 and n3 is zero and the other is 1, especially those wherein R2 is H or xe2x80x94CH2xe2x80x94CH2xe2x80x94OH.
One suitable genus of hydroxamate compounds are those of formula Ia: 
wherein
n4 is 0-3,
R2 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, alkylcycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, xe2x80x94(CH2)nC(O)R6, amino acyl and xe2x80x94(CH2)nR7;
R5xe2x80x2 is heteroaryl, heteroarylalkyl (e.g., pyridylmethyl), aromatic polycycles, non-aromatic polycycles, mixed aryl and non-aryl polycycles, polyheteroaryl, or mixed aryl and non-aryl polyheterocycles,
or a pharmaceutically acceptable salt thereof.
Another suitable genus of hydroxamate compounds are those of formula Ia: 
wherein
n4 is 0-3,
R2 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, alkylcycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, xe2x80x94(CH2)nC(O)R6, amino acyl and xe2x80x94(CH2)nR7;
R5xe2x80x2 is aryl, arylalkyl, aromatic polycycles, non-aromatic polycycles, and mixed aryl and non-aryl polycycles; especially aryl, such as p-fluorophenyl, p-chlorophenyl, p-O-C1-C4-alkylphenyl, such as p-methoxyphenyl, and p-C1-C4-alkylphenyl; and arylalkyl, such as benzyl, ortho, meta or para-fluorobenzyl, ortho, meta or para-chlorobenzyl, ortho, meta or para-mono, di or tri-O-C1-C4-alkylbenzyl, such as ortho, meta or para-methoxybenzyl, m,p-diethoxybenzyl, o,m,p-triimethoxybenzyl , and ortho, meta or para- mono, di or tri C1-C4-alkylphenyl, such as p-methyl, m,m-diethylphenyl,
or a pharmaceutically acceptable salt thereof.
Another interesting genus are the compounds of formula Ib: 
wherein
R2xe2x80x2 is selected from H, C1-C6 alkyl, C4-C6 cycloalkyl, cycloalkylalkyl (e.g., cyclopropylmethyl), (CH2)2-4OR21 where R21 is H, methyl, ethyl, propyl, and i-propyl, and
R5xe2x80x3 is unsubstituted 1H-indol-3-yl, benzofuran-3-yl or quinolin-3-yl, or substituted 1H-indol-3-yl, such as 5-fluoro-1H-indol-3-yl or 5-methoxy-1H-indol-3-yl, benzofuran-3-yl or quinolin-3-yl,
or a pharmaceutically acceptable salt thereof.
Another interesting genus of hydroxamate compounds are the compounds of formula (Ic) 
wherein
the ring containing Z1 is aromatic or non-aromatic, which non-aromatic rings are saturated or unsaturated,
Z1 is O, S or Nxe2x80x94R20,
R18 is H, halo, C1-C6alkyl (methyl, ethyl, t-butyl), C3-C7cycloalkyl, aryl, for example unsubstituted phenyl or phenyl substituted by 4-OCH3 or 4-CF3, or heteroaryl, such as 2-furanyl, 2-thiophenyl or 2-, 3- or 4-pyridyl;
R20 is H, C1-C6alkyl, C1-C6alkyl-C3-C9cycloalkyl (e.g., cyclopropylmethyl), aryl, heteroaryl, arylalkyl (e.g., benzyl), heteroarylalkyl (e.g., pyridylmethyl), acyl (acetyl, propionyl, benzoyl) or sulfonyl (methanesulfonyl, ethanesulfonyl, benzenesulfonyl, toluenesulfonyl) A1 is 1, 2 or 3 substituents which are independently H, C1-C-6alkyl, xe2x80x94OR9, halo, alkylamino, aminoalkyl, halo, or heteroarylalkyl (e.g., pyridylmethyl),
R19 is selected from H, C1-C6alkyl, C4-C9cycloalkyl, C4-C9heterocycloalkyl, aryl, heteroaryl, arylalkyl (e.g., benzyl), heteroarylalkyl (e.g., pyridylmethyl) and xe2x80x94(CH2CHxe2x95x90CH(CH3)(CH2))1-3H;
R2 is selected from H, C1-C6 alkyl, C4-C9 cycloalkyl, C4-C9 heterocycloalkyl, alkylcycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, xe2x80x94(CH2)nC(O)R6, amino acyl and xe2x80x94(CH2)nR7;
v is 0, 1 or 2,
p is 0-3, and
q is 1-5 and r is 0 or
q is 0 and r is 1-5,
or a pharmaceutically acceptable salt thereof. The other variable substituents are as defined above.
Especially useful compounds of formula (Ic) are those wherein R2 is H, or xe2x80x94(CH2)pCH2OH, wherein p is 1-3, especially those wherein R1 is H; such as those wherein R1 is H and X and Y are each H, and wherein q is 1-3 and r is 0 or wherein q is 0 and r is 1-3, especially those wherein Z1 is Nxe2x80x94R20. Among these compounds R2 is preferably H or xe2x80x94CH2xe2x80x94CH2xe2x80x94OH and the sum of q and r is preferably 1.
Another interesting genus of hydroxamate compounds are the compounds of formula (Id) 
wherein
Z1 is O, S or Nxe2x80x94R20,
R18 is H, halo, C1-C6alkyl (methyl, ethyl, t-butyl), C3-C7cycloalkyl, aryl, for example, unsubstituted phenyl or phenyl substituted by 4-OCH3 or 4-CF3, or heteroaryl,
R20 is H, C1-C6alkyl, C1-C6alkyl-C3-C9cycloalkyl (e.g., cyclopropylmethyl), aryl, heteroaryl, arylalkyl (e.g., benzyl), heteroarylalkyl (e.g., pyridylmethyl), acyl (acetyl, propionyl, benzoyl) or sulfonyl (methanesulfonyl, ethanesulfonyl, benzenesulfonyl, toluenesulfonyl),
A1 is 1, 2 or 3 substituents which are independently H, C1-C-6alkyl, xe2x80x94OR19, or halo,
R19 is selected from H, C1-C6alkyl, C4-C9cycloalkyl, C4-C9heterocycloalkyl, aryl, heteroaryl, arylalkyl (e.g., benzyl), and heteroarylalkyl (e.g., pyridylmethyl);
p is 0-3, and
q is 1-5 and r is 0 or
q is 0 and r is 1-5,
or a pharmaceutically acceptable salt thereof. The other variable substituents are as defined above.
Especially useful compounds of formula (Id) are those wherein R2 is H, or xe2x80x94(CH2)pCH2OH, wherein p is 1-3, especially those wherein R1 is H; such as those wherein R1 is H and X and Y are each H, and wherein q is 1-3 and r is 0 or wherein q is 0 and r is 1-3. Among these compounds R2 is preferably H or xe2x80x94CH2xe2x80x94CH2xe2x80x94OH and the sum of q and r is preferably 1.
The present invention further relates to compounds of the formula (Ie) 
or a pharmaceutically acceptable salt thereof. The variable substituents are as defined above.
Especially useful compounds of formula (Ie) are those wherein R8 is H, fluoro, chloro, bromo, a C1-C4alkyl group, a substituted C1-C4alkyl group, a C3-C7cycloalkyl group, unsubstituted phenyl, phenyl substituted in the para position, or a heteroaryl (e.g., pyridyl) ring.
Another group of useful compounds of formula (Ie) are those wherein R2 is H, or xe2x80x94(CH2)pCH2OH, wherein p is 1-3, especially those wherein R1 is H; such as those wherein R1 is H and X and Y are each H, and wherein q is 1-3 and r is 0 or wherein q is 0 and r is 1-3. Among these compounds R2 is preferably H or xe2x80x94CH2xe2x80x94CH2OH and the sum of q and r is preferably 1.
Another group of useful compounds of formula (le) are those wherein R18 is H, methyl, ethyl, t-butyl, trifluoromethyl, cyclohexyl, phenyl, 4-methoxyphenyl, 4-trifluoromethylphenyl, 2-furanyl, 2-thiophenyl, or 2-, 3- or 4-pyridyl wherein the 2-furanyl, 2-thiophenyl and 2-, 3or 4-pyridyl substituents are unsubstituted or substituted as described above for heteroaryl rings; R2 is H, or xe2x80x94(CH2)pCH2OH, wherein p is 1-3; especially those wherein R1 is H and X and Y are each H, and wherein q is 1-3 and r is 0 or wherein q is 0 and r is 1-3. Among these compounds R2 is preferably H or xe2x80x94CH2xe2x80x94CH2xe2x80x94OH and the sum of q and r is preferably 1.
Those compounds of formula le wherein R20 is H or C1-C6alkyl, especially H, are important members of each of the subgenuses of compounds of formula Ie described above.
N-hydroxy-3-[4-[[(2-hydroxyethyl)[2-(1H-indol-3-yl)ethyl]-amino]methyl]phenyl]-2E-2-propenamide, N-hydroxy-3-[4-[[[2-(1H-indol-3-yl)ethyl]-amino]methyl]phenyl]-2E-2-propenamide and N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide, or a pharmaceutically acceptable salt thereof, are important compounds of formula (Ie).
The present invention further relates to the compounds of the formula (If): 
or a pharmaceutically acceptable salt thereof. The variable substituents are as defined above.
Useful compounds of formula (If) are include those wherein R2 is H, or xe2x80x94(CH2)pCH2OH, wherein p is 1-3, especially those wherein R1 is H; such as those wherein R1 is H and X and Y are X each H, and wherein q is 1-3 and r is 0 or wherein q is 0 and r is 1-3. Among these compounds R2 is preferably H or xe2x80x94CH2xe2x80x94CH2xe2x80x94OH and the sum of q and r is preferably 1.
N-hydroxy-3-[4-[[[2-(benzofur-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide, or a pharmaceutically acceptable salt thereof, is an important compound of formula (If).
The compounds described above are often used in the form of a pharmaceutically acceptable salt. Pharmaceutically acceptable salts include, when appropriate, pharmaceutically acceptable base addition salts and acid addition salts, for example, metal salts, such as alkali and alkaline earth metal salts, ammonium salts, organic amine addition salts, and amino acid addition salts, and sulfonate salts. Acid addition salts include inorganic acid addition salts such as hydrochloride, sulfate and phosphate, and organic acid addition salts such as alkyl sulfonate, arylsulfonate, acetate, maleate, fumarate, tartrate, citrate and lactate. Examples of metal salts are alkali metal salts, such as lithium salt, sodium salt and potassium salt, alkaline earth metal salts such as magnesium salt and calcium salt, aluminum salt, and zinc salt. Examples of ammonium salts are ammonium salt and tetramethylammonium salt. Examples of organic amine addition salts are salts with morpholine and piperidine. Examples of amino acid addition salts are salts with glycine, phenylalanine, glutamic acid and lysine. Sulfonate salts include mesylate, tosylate and benzene sulfonic acid salts.
As is evident to those skilled in the art, the many of the deacetylase inhibitor compounds of the present invention contain asymmetric carbon atoms. It should be understood, therefore, that the individual stereoisomers are contemplated as being included within the scope of this invention.
The hydroxamate compounds of the present invention can be produced by known organic synthesis methods. For example, the hydroxamate compounds can be produced by reacting methyl 4-formyl cinnamate with tryptamine and then converting the reactant to the hydroxamate compounds. As an example, methyl 4-formyl cinnamate 2, is prepared by acid catalyzed esterification of 4-formylcinnamic acid 3 (Bull. Chem. Soc. Jpn. 1995; 68:2355-2362). An alternate preparation of methyl 4-formyl cinnamate 2 is by a Pd-catalyzed coupling of methyl acrylate 4 with 4-bromobenzaldehyde 5. 
Additional starting materials can be prepared from 4-carboxybenzaldehyde 6, and an exemplary method is illustrated for the preparation of aldehyde 9, shown below. The carboxylic acid in 4-carboxybenzaldehyde 6 can be protected as a silyl ester (e.g., the t-butyldimethylsilyl ester) by treatment with a silyl chloride (e.g., t-butyldimethylsilyl chloride) and a base (e.g. triethylamine) in an appropriate solvent (e.g., dichloromethane). The resulting silyl ester 7 can undergo an olefination reaction (e.g., a Homer-Emmons olefination) with a phosphonate ester (e.g., triethyl 2-phosphonopropionate) in the presence of a base (e.g., sodium hydride) in an appropriate solvent (e.g., tetrahydrofuran (THF)). Treatment of the resulting diester with acid (e.g., aqueous hydrochloric acid) results in the hydrolysis of the silyl ester providing acid 8. Selective reduction of the carboxylic acid of 8 using, for example, borane-dimethylsuflide complex in a solvent (e.g., THF) provides an intermediate alcohol. This intermediate alcohol could be oxidized to aldehyde 9 by a number of known methods, including, but not limited to, Swern oxidation, Dess-Martin periodinane oxidation, Moffatt oxidation and the like. 
The aldehyde starting materials 2 or 9 can be reductively aminated to provide secondary or tertiary amines. This is illustrated by the reaction of methyl 4-formyl cinnamate 2 with tryptamine 10 using sodium triacetoxyborohydride (NaBH(OAc)3) as the reducing agent in dichloroethane (DCE) as solvent to provide amine 11. Other reducing agents can be used, e.g., sodium borohydride (NaBH4) and sodium cyanoborohydride (NaBH3CN), in other solvents or solvent mixtures in the presence or absence of acid catatylysts (e.g., acetic acid and trifluoroacetic acid). Amine 11 can be converted directly to hydroxamic acid 12 by treatment with 50% aqueous hydroxylamine in a suitable solvent (e.g., THF in the presence of a base, e.g., NaOH). Other methods of hydroxamate formation are known and include reaction of an ester with hydroxylamine hydrochloride and a base (e.g., sodium hydroxide or sodium methoxide) in a suitable solvent or solvent mixture (e.g., methanol, ethanol or methanol/THF). 
Aldehyde 2 can be reductively aminated with a variety of amines, exemplified by, but not limited to, those illustrated in Table 1. The resulting esters can be converted to target hydroxamates by the methods listed.
An alternate synthesis of the compounds of this invention starts by reductive amination of 4-formyl cinnamic acid 3, illustrated below with 3-phenylpropylamine 13, using, for example, NaBH3CN as the reducing agent in MeOH and HOAc as a catalyst. The basic nitrogen of the resulting amino acid 14 can be protected, for example, as t-butoxycarbamate (BOC) by reaction with di-t-butyldicarbonate to give 15. 
The carboxylic acid can be coupled with a protected hydroxylamine (e.g., O-trityl hydroxylamine) using a dehydrating agent (e.g., 1-(3-dimethylaminopropyl)-3ethylcarbodiimide hydrochloride (EDCI)) and a catalyst (e.g., 1-hydroxybenzotriazole hydrate (HOBT)) in a suitable solvent (e.g., DMF) to produce 16. Treatment of 16 with a strong acid (e.g., trifluoroacetic acid (TFA)) provides a hydroxamic acid 17 of the present invention. Additional examples of compounds that can be prepared by this method are: 
Tertiary amine compounds can be prepared by a number of methods. Reductive amination of 30 with nicotinaldehyde 32 using NaBH3CN as the reducing agent in dichloroethane and HOAc as a catalyst provides ester 34. Other reducing agents can be used (e.g., NaBH4 and NaBH(OAc)3) in other solvents or solvent mixtures in the presence or absence of acid catalysts (e.g., acetic acid, trifluoroacetic acid and the like). Reaction of ester 34 with HONH2.HCl, NaOH in MeOH provides hydroxamate 36. 
Tertiary amine compounds prepared by this methodology are exemplified, but not limited to, those listed in Table 2.
An alternate method for preparing tertiary amines is by reacting a secondary amine with an alkylating agent in a suitable solvent in the presence of a base. For example, heating a dimethylsulfoxide (DMSO) solution of amine 11 and bromide 40 in the presence of (i-Pr)2NEt yielded tertiary amine 42. Reaction of the tertiary amine 42 with HONH2.HCl, NaOH in MeOH provides hydroxamate 43. The silyl group can be removed by any method known to those skilled in the art. For example, the hydroxamate 43 can be treated with an acid, e.g., trifluoroacetic acid, or fluoride to produce hydroxyethyl compound 44. 
The hydroxamate compound, or salt thereof, is suitable for preparing pharmaceutical compositions, especially pharmaceutical compositions having deacetylase, especially histone deacetylase, inhibiting properties. Studies with athymic mice demonstrate that the hydroxamate compound causes HDA inhibition and increased histone acetylation in vivo, which triggers changes in gene expression that correlate with tumor growth inhibition.
The present invention further includes pharmaceutical compositions comprising a pharmaceutically effective amount of one or more of the above-described compounds as active ingredient. Pharmaceutical compositions according to the invention are suitable for enteral, such as oral or rectal, and parenteral administration to mammals, including man, for the treatment of tumors, alone or in combination with one or more pharmaceutically acceptable carriers.
The hydroxamate compound is useful in the manufacture of pharmaceutical compositions having an effective amount the compound in conjunction or admixture with excipients or carriers suitable for either enteral or parenteral application. Preferred are tablets and gelatin capsules comprising the active ingredient together with (a) diluents; (b) lubricants, (c) binders (tablets); if desired, (d) disintegrants; and/or (e) absorbents, colorants, flavors and sweeteners. Injectable compositions are preferably aqueous isotonic solutions or suspensions, and suppositories are advantageously prepared from fatty emulsions or suspensions. The compositions may be sterilized and/or contain adjuvants, such as preserving, stabilizing, wetting or emulsifying agents, solution promoters, salts for regulating the osmotic pressure and/or buffers. In addition, the compositions may also contain other therapeutically valuable substances. The compositions are prepared according to conventional mixing, granulating or coating methods, respectively, and contain preferably about 1 to 50% of the active ingredient.
Suitable formulations also include formulations for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain antioxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The formulations may be presented in unit-dose or multi-dose containers, for example, sealed ampules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example, water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.
As discussed above, the compounds of the present invention are useful for treating proliferative diseases. A proliferative disease is mainly a tumor disease (or cancer) (and/or any metastases). The inventive compounds are particularly useful for treating a tumor which is a breast cancer, genitourinary cancer, lung cancer, gastrointestinal cancer, epidermoid cancer, melanoma, ovarian cancer, pancreas cancer, neuroblastoma, head and/or neck cancer or bladder cancer, or in a broader sense renal, brain or gastric cancer; in particular (i) a breast tumor; an epidermoid tumor, such as an epidermoid head and/or neck tumor or a mouth tumor; a lung tumor, for example a small cell or non-small cell lung tumor; a gastrointestinal tumor, for example, a colorectal tumor; or a genitourinary tumor, for example, a prostate tumor (especially a hormone-refractory prostate tumor); or (ii) a proliferative disease that is refractory to the treatment with other chemotherapeutics; or (iii) a tumor that is refractory to treatment with other chemotherapeutics due to multidrug resistance.
In a broader sense of the invention, a proliferative disease may furthermore be a hyperproliferative condition such as leukemias, hyperplasias, fibrosis (especially pulmonary, but also other types of fibrosis, such as renal fibrosis), angiogenesis, psoriasis, atherosclerosis and smooth muscle proliferation in the blood vessels, such as stenosis or restenosis following angioplasty.
Where a tumor, a tumor disease, a carcinoma or a cancer are mentioned, also metastasis in the original ,organ or tissue and/or in any other location are implied alternatively or in addition, whatever the location of the tumor and/or metastasis.
The compound is selectively toxic or more toxic to rapidly propiferating cells than to normal cells, particularly in human cancer cells, e.g., cancerous tumors, the compound has significant antiproliferative effects and promotes differentiation, e.g., cell cycle arrest and apoptosis. In addition, the hydroxamate compound induces p21, cyclin-CDK interacting protein, which induces either apoptosis or G1 arrest in a variety of cell lines.
The following examples are intended to illustrate the invention and are not to be construed as being limitations thereto.